A rapid HPLC/ESI-MS/MS method for quantitative analysis of isovalerylshikonin in rat plasma.

A new, fast and sensitive high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS) method was developed and validated for isovalerylshikonin in rat plasma using emodin as internal standard (IS). The analyte was extracted from rat plasma with ethyl acetate, after 10% HCl treatment and protein precipitated by methanol. The compound was separated on an Ultimate XB-C(18) analytical column using a mobile phase of methanol-10 mM ammonium acetate in water-acetonitrile containing 0.05% formic acid (45 : 10 : 45, v/v/v) with isogradient elution. The analyte was detected in negative ion mode using multiple-reaction monitoring. The method was validated and the specificity, linearity, lower limit of quantitation (LLOQ), precision, accuracy, recoveries and stability were determined. LLOQ was 9 ng/mL for isovalerylshikonin. Correlation coefficient (r) value for the linear range of the analyte was greater than 0.99. The intra-day and inter-day precision and accuracy were better than 8.52%. The relative and absolute recovery was above 86% and no matrix effects were observed for isovalerylshikonin. This validated method provides a modern, rapid and robust procedure for the pharmacokinetic study of the two compounds in rats after intravenous administration to rats (n = 4).

Zhu M ，Gao Y ，Wu Z ，Zhao Y ... -  《-》

Quantitative determination of zidovudine diaryl phosphate triester pro-drugs in rat plasma by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry.

Zhu M ，Xie B ，Tang G ，Hu A ，Fang M ，Wu Z ，Zhao Y ... -  《JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS》

Liquid chromatography tandem mass spectrometry pharmacokinetic study of DL-praeruptorin A in rat plasma.

DL-praeruptorin A is a novel drug with valuable apoptosis and inflammation inhibitory effects in cardiac muscle. Previous pharmacokinetic studies of DL-praeruptorin A have had limited success due to its very low plasma concentrations. In this study, we developed and validated a new rapid, sensitive and specific high-performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS) method for quantitative analysis of dl-praeruptorin A in rat plasma. DL-Praeruptorin A and diazepam (internal standard) extracted from rat plasma samples with chloroform and analyzed on an XTerra™ RP₁₈ column (150 mm x 4.6 mm i.d., 5 µm) were chromatographically separated within 5.5 min using methanol-water (75:25, v/v; flow rate 1 mL/min) as the mobile phase. DL-praeruptorin A was detected in positive ion mode using multiple reaction monitoring. The method was validated and the specificity, linearity, lower limit of quantitation (LLOQ, 2.5 ng/mL), precision (intra- and inter-day <11.0%), accuracy (90.2-96.3%), recovery (>79.2%) and stability were determined. The correlation coefficient (r²) for the linear range of 2.5-2500.0 ng/mL was >0.999. No matrix effects were observed. The validated method was successfully applied to pharmacokinetic studies of dl-praeruptorin A after intravenous administration to rats. The LLOQ obtained with this method was lower than in previous studies and could be valuable for determination of dl-praeruptorin A in therapeutic drug monitoring and preclinical studies to establish appropriate dose and frequency.

Ruan H ，Zhang Z ，Zhu X 《-》

Sensitive liquid chromatography/tandem mass spectrometry method for the determination of the lipophilic antipsychotic drug chlorpromazine in rat plasma and brain tissue.

Zhang G ，Terry AV Jr ，Bartlett MG 《JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES》

Liquid chromatography/tandem mass spectrometry method for the simultaneous determination of olanzapine, risperidone, 9-hydroxyrisperidone, clozapine, haloperidol and ziprasidone in rat plasma.

Zhang G ，Terry AV Jr ，Bartlett MG 《RAPID COMMUNICATIONS IN MASS SPECTROMETRY》